Specifically, the project seeks to develop, demonstrate, and monitor energy-saving ventilation solutions that incorporate the recirculation of return air. When using ventilation without recirculation, the whole volume of conditioned air is exchanged at a variable rate with outdoor air that must be conditioned before being supplied in the room.
If a share of this extracted air volume can be reused, the need for conditioning can be reduced. The project aspires to establish new standards for ventilation systems that can save energy without compromising the health and comfort of building occupants.
How Does the Project Work?
Recirculate IT tackles its ambitious goals via theoretical research, simulations, laboratory tests, and full-scale demonstrations in various building types. The project is organized into four interrelated work packages (WPs) that guide the research and development process.
1. Development of Control Strategies
A central part of the project is the development of advanced control systems that integrate energy efficiency and indoor air quality (IAQ). This involves co-simulation with EnergyPlus, CONTAM, and Python to optimize ventilation settings to save energy while rising indoor air humidity in winter and reducing pollutant exposure.
Simulations will be used to study heat recovery and recirculation of the return air, and trade-offs for heating/cooling supply to control recirculation while full conditioning with ventilation, as well as combinations of these. These strategies will be tested in two real buildings (pilot sites) to validate their effectiveness.
2. Predictive Control and Energy Flexibility
This involves analyzing data on various pollutants and integrating these insights into rule-based predictive controls (RBPC) that manage the ventilation system’s energy use dynamically. The aim is to ensure that buildings can adjust their energy consumption in response to external factors like peak demand periods while keeping IAQ within healthy levels.
3. Risk Assessment and IAQ
Another important aspect of the project is assessing the risks associated with the use of recirculated air. This involves measuring various air pollutants, including microorganisms and chemical compounds, both indoors and in return ventilation systems. The goal is to develop a comprehensive understanding of which pollutants need to and can be controlled to ensure that air recirculation does not compromise the health of the building's occupants.
4. Pilot Projects and Demonstrations
To validate the theoretical models and simulations, full-scale tests are conducted in two real buildings, such as office buildings, factories and cultural centers. These pilot projects provide valuable data that are used to refine and improve the control strategies before they can be more widely implemented.
What is unique about the project?
Recirculate IT is a pioneering project that combines energy savings with the maintenance of high indoor air quality through smart control of air recirculation in ventilation systems.
The project aims to fill a critical knowledge gap in current research by documenting the energy-saving potential, while simultaneously addressing the health risks that may arise from air recirculation. This work could lead not only to reduced energy use and lower climate impact, but also to improved well-being and health for building occupants.
In addition to technological development, the project aims to educate future experts in ventilation and indoor air quality (IAQ) by involving students in the research and broadly disseminating the results. This includes open publications, seminars, and direct collaboration with industry partners and policymakers to ensure that the knowledge is applied and has the greatest possible impact on practice and policy.
Through these efforts, wehope to pave the way for more energy-efficient and health-promoting buildings that are equipped to meet future energy demands and climate challenges.